一种检测相控阵天线移相单元的新方法

提出了一种新的定量检测相控阵雷达天线移相单元的方法,使系统的检测维护诊断有了可靠的依据.     

Optical True Time-Delay for Two-Dimensional X -Band Phased Array Antennas

An optical true time-delay (TTD) scheme for two-dimensional (2-D) X-band phased array antennas (PAAs) has been proposed. It is composed of a multiwavelength optical source and a delay line matrix consisting of 2times2 optical microelectromechanical system (MEMS) switches with fiber-optic delay lines connected between cross ports. A 2-bit times 4-bit optical TTD for 10-GHz 2-D PAAs has been implemented by cascading a wavelength-dependent TTD (WD-TTD) with a unit time delay of 12 ps in the x-direction and a wavelength-independent TTD (WI-TTD) with that of 6 ps in the y-direction. The time delay error for WD-TTD was measured to be less than 2.8 ps, mainly due to jitter incurred from gain-switching. On the other hand, the error for WI-TTD was less than 0.8 ps, which is within the equipment resolution. Insertion loss of both delay line matrices was less than 1 dB due to the column-wise control of the MEMS switches. This prevents the feed current applied to each antenna element from fluctuating at any radiation angles so that antenna gain and sidelobe level do not deteriorate in this scheme     

A Novel Implementation Technique of Conical Scan Radar Using A Programmable Phased Array

In radar, planar phased array antenna plays vital role in electronic scanning in the azimuth and elevation direction to the horizon. In most operations using planar phased array both the coordinates of azimuth and elevation, are steered electronically. In this paper a conceptual schematic of a phased array antenna with programmable time delay units has been presented. It is shown that by suitably exploiting the time delay matrix one can have electronic beam rotation around the target axis as required in conical scan. Thus both the elevation and azimuth motors in conical scan system are replaced by electronic scanning. Heuristically, we have selected eight consecutive points for beam rotation in a polygon shape and can also be extended almost circular shape by increasing number of array elements and phase shifter (delays) in the delay matrix. The array requires dual control of phase gradient and individual phase values. The whole array is controlled by micro-controller. This presents exciting possibilities in radar operation.     

High-Efficiency Angled-Dipole Antennas for Millimeter-Wave Phased Array Applications

A high-efficiency microstrip-fed endfire angled-dipole antenna has been developed for millimeter-wave phased array applications. The antenna is built on both sides of a Teflon substrate (epsiv_r = 2.2) and this allows a wideband feed from the single-ended microstrip line to the differential dipole. The design results in wide radiation patterns for scanning purposes with a gain of around 2.5 dB at 20-26 GHz and a cross-polarization level of < -15 dB at 24 GHz. A mutual coupling of < -23 dB is measured between adjacent elements with 6.8 mm center-to center spacing (0.50-0.54 lambda₀ at 22-24 GHz). A variant of the angled-dipole antenna with a magnetic ground plane edge was also developed, and shows a measured gain of > 6 dB at 23.2-24.6 GHz and very low mutual coupling between elements (<-23 dB for a 6.8 mm spacing). Both antennas result in a radiation efficiency of > 93% when referenced to the microstrip line feed (including mismatch loss). The usefulness of these antennas as phased array radiators is demonstrated by several eight-element linear arrays at 22-24 GHz with scan angle up to 50 degrees. The application areas are in automotive radars and high data-rate communication systems.     

共形相控阵天线的应用与关键技术

相控阵天线技术在雷达、通信、电子战、导航等领域获得了广泛应用和高速发展,共形相控阵天线是相控阵天线发展的重点之一。文中讨论了共形相控阵天线在雷达、通信、电子战等领域的广泛应用前景及推动共形相控阵天线发展的主要原因,进而探讨了共形相控阵天线波束形成与扫描的原理及实现共形相控阵天线的一些关键技术。     

相控阵雷达与光控相控阵雷达

对在国际军备竞争中占据了重要地位的雷达作了全面的概述。针对传统机械扫描雷达扫描速度缓慢、精度低、可靠性不高等缺点引出了当今研究热点相控阵雷达，阐述了其工作原理及优缺点，并指出随着现代国际形势的发展传统相控阵雷达所暴露出的无法适应宽带宽需求的缺陷。在此情况下光控相控阵雷达应运而生，描述了光控相控阵雷达中的关键技术-光学真延时技术的原理，归纳了光学真延时技术的各种实现方案，并简述了国际上光控相控阵雷达的发展历程。     

Integrated Electro-Absorption Modulation DFB Laser Based Optical True Time-Delay Feeder for X-Band Phased Array Antennas

A 4-bit optical true-time-delay feeder incorporating an integrated electro-absorption modulation distributed feedback (DFB) laser for X-band phased array antennas is demonstrated. The integrated electro-absorption modulation DFB laser is an attractive device that provides a very compact, low-cost solution for optical true-time-delay systems. The variable delay line is constructed by cascaded magneto-optic switches, which have fast switching speed. The integrated electro-absorption modulation DFB laser system shows high signal-to-noise ratio up to 58dB, and the transmission performance of the system is relatively good and accredited.     

数字相控阵与模拟相控阵雷达的性能对比分析

对比传统的有源相控阵雷达,探讨了数字有源相控阵面临的诸多难题,如宽带、反干扰、数字T/R组件和超低副瓣等,以期对数字有源相控阵雷达的优缺点及进一步的研究重点有一个更加全面的认识。     

超宽角度圆极化天线及其相控阵研究

宽角度圆极化天线及其阵列可以广泛应用于车载、机载和星载雷达系统等很多方面,用以在更宽空间范围内接收或发射电磁波。本文提出了一种宽角圆极化微带天线,并在此基础上设计了一个1×4 单元的宽角度圆极化扫描直线阵列。该阵列具有结构紧凑、重量轻和宽角度范围内实现圆极化扫描等突出优点。     

传感器管理及其在相控阵雷达中的应用

传感器管理是数据融合的一部分。介绍了传感器管理的概念和框架 ,概述了国内外传感器管理算法的研究现状。主要工作是针对相控阵雷达这一传感器 ,通过对其不同工作模式以及不同参数的管理 ,来说明传感器管理的原理。提出了一种新的自适应采样周期算法 ,仿真结果表明该算法的优越性     

虚像相位阵列的二维成像原理及其应用

虚像相位阵列（VIPA：virtually-imaged phased array）是一种具有大角度色散的光学器件,利用其大角色散的特性,可以用来制作高分辨率滤波器和色散补偿器。将虚像相位阵列和衍射光栅结合实现二维成像是光谱处理领域的重大进步。从二维成像原理出发,详细介绍其在研制高分辨率和高信噪比的光学滤波器、实现复杂的二维光谱处理以及光谱成像等研究领域的最新应用。     

1kb超高速内容联想存储器的设计

超高速内容联想存储器（ＣＡＳＭ）是一种将ＲＡＭ和ＣＡＭ功能集于一体的特种存储器，分析了ＣＡＳＭ存储单元的结构，分别阐述了顺序写，顺序法，联想写和联想读四种工作模式下的工作原理，最后给出了优化设计和模拟结果。     

现场可编程滤波器阵列单元

通过对通用数字滤波器公式的细致分析，建立了一种最为精简实用的滤波器模块单元，给出了模拟结果，进而提出了编程滤波器阵列单元的概念，提供了在实用数字滤波的具体实现中比数字信号处理（ＤＳＰ）更直接，更高效的途径。     

相控阵天线单元研究

文章研究了一种新型的、带有高阻抗环检测天线的印刷偶极子相控阵天线单元。其特点是可利用检测天线与单元天线之间的传输关系，准确反映单元天线的动态特性。这种天线的应用对研究相控阵天线的实时检测问题十分有用     

一种用于相控阵雷达的多通道接收机

分析了雷达系统的需求,介绍了一种用于相控阵雷达的多通道接收机,对接收机指标进行了计算,重点分析了接收链路的增益分配、线性频率调制(LFM)信号的实现和Ku波段本振源的低相噪设计,并优化了接收机的抗振性能。测试结果表明接收机的主要技术指标满足系统要求,整个方案合理、可行。     

一款具有稳定扫描波束分辨率的宽视角相控阵天线北大核心CSCD

基于自适应稀疏阵的结构,提出了一种具有宽视角与稳定扫描波束分辨率性能的相控阵天线。阵列单元是可以在相同谐振频率下实现TM;和TM;两种模式共同工作的单激励圆环贴片天线,其具有140°的半功率波束宽度,这种宽波束辐射效果能够较好地拓展相控阵天线的扫描范围。基于此单元构建了一个35元线阵,对其波束扫描分析发现在限定增益波动小于2 dB的条件下阵列扫描范围可以达到-70°~+70°,但主瓣波束宽度随着扫描角度的增加而增大。为解决这个问题,引入了自适应稀疏阵的概念,并采用基于互耦补偿矩阵的迭代快速傅里叶变换(Iterative Fast Fourier Transform,IFFT)技术进行自适应稀疏阵的优化设计。结果表明,所提出的基于自适应稀疏阵结构的35单元相控阵天线在-60°~+60°扫描范围内增益波动始终小于1.5 dB,波束宽度波动小于1°,且峰值旁瓣电平基本保持在-20 dB以下。相较于均匀周期阵列,所提出的自适应稀疏相控阵天线能够在实现低旁瓣宽视角扫描的同时,有效提高天线在宽角度范围内扫描波束分辨率的稳定性。     

机载相控阵雷达天线阵的可靠性新模型

影响机载相控阵雷达下视能力的一个重要指标是天线的超低副瓣特性。在传统的机载相控阵雷达天线的可靠性设计中是对n中取女的表决模型冗余量进行压缩,该方法没有考虑失效T／R组件的分布位置对天线超低副瓣性能的影响。通过数学归纳法建立了在收发组件失效分布约束奢件下,机载相控阵雷达天线阵的可靠性数学模型。该模型的正确性经过了仿真验证。通过实例比较说明了传统可靠性设计方法可能带来的工程设计风险。该模型可用来指导机载相控阵天线的可靠性设计。     

A Modular and Lightweight Multibeam Active Phased Receiving Array for Satellite Applications: Design and Ground Testing

A 17 GHz receiving multibeam active phased array, based on modular “suopertiles,” was built and tested. The array was launched and placed in geostationary orbit in 2008. The tile concept is characterized by low volume and low mass, making it well suited for satellite-antenna applications, and in particular for deployed multibeam active phased arrays for communications satellites. The modular design facilitates low recurring cost in a high-volume continuous production. Both component and array measurement data are presented in the paper. Measured array-antenna patterns were in good agreement with estimated and predicted values, proving that the array can be built according to its requirements, and calibrated and controlled to generate independent beams with low sidelobes from low-rms excitation errors.     

Ultrawideband Double Rhombus Antenna With Stable Radiation Patterns for Phased Array Applications

A broadband microstrip-fed printed antenna is proposed for phased antenna array systems. The antenna consists of two parallel-modified dipoles of different lengths. The regular dipole shape is modified to a quasi-rhombus shape by adding two triangular patches. Using two dipoles helps maintain stable radiation patterns close to their resonance frequencies. A modified array configuration is proposed to further enhance the antenna radiation characteristics and usable bandwidth. Scanning capabilities are studied for a four-element array. The proposed antenna provides endfire radiation patterns with high gain, high front-to-back (F-to-B) ratio, low cross-polarization level, wide beamwidth, and wide scanning angles in a wide bandwidth of 103%     

PLA模拟的一种方法

随着计算机系统规模和设计复杂性的增加，VLSI，PLA的发展愈来愈有吸引力。文中分析了用于PLA逻辑模拟上的传统逻辑模拟的缺陷，进一步导出了使用阵列实现PLA模拟的一种方法。这个方法提高了模拟速度，节省了存贮空间。用这种方法实现PLA，编程容易，算法清楚，易读。